Heart failure is a condition in which the heart can't pump blood the way it should. In some cases, the heart can't fill with enough blood. In other cases, the heart can't send blood to the rest of the body with enough force. Some people have both problems.
Heart failure affects at least 5 million people in the United States alone.
Heart failure can involve systolic impairment or diastolic impairment or both. In systolic dysfunction, the heart does not pump with enough force and fails to provide tissue with adequate circulatory output.
Diastolic impairment involves resistance to ventricular filling. Diastole is the period of time during which the heart is relaxed and is filling with blood. Thus, diastolic impairment involves the heart's inability to properly relax. It usually means the heart wall is stiff, and it directly relates to ventricular diastolic pressure. Diastolic impairment is generally associated with longer ventricular relaxation time.
About 20-40% of heart failure cases involve diastolic impairment.